1. Field of the Invention
This invention relates to a reversible hammer mill having compound adjustable breaker plates that are able to handle bulky and large size objects as well as trash and light weight material requiring reduction in a downdraft pass through the mill.
2. Description of the Prior Art
A consistent problem with prior art hammer mills is that the breaker bars and plates are installed with limited ability to provide an opening large enough to receive bulky objects irrespective of the direction of rotation of the hammer rotor. This problem is typical of such prior art mills as are shown in Stine et al Pat. No. 2,411,302 of Nov. 19, 1946 or West Pat. No. 2,767,929 of Oct. 23, 1956 or Fawcett Pat. No. 2,977,055 of Mar. 28, 1961 or Williams Pat. No. 4,767,066 of Aug. 30, 1988.
While reversibility of a hammer rotor is desirable, the construction of hammer mills capable of being reversed has resulted in complicated and expensive provisions to achieve reversibility while not providing any protection for the conveyor head shaft feeding the mill. One example is seen in Williams Pat. No. 3,667,694 of Jun. 6, 1972 which is provided with an elongated feed stack and protective curtain for the feed conveyor when difficult objects are to be reduced by the rotating hammer action. Other examples of expensive mill construction that do not protect the headshaft of a feed conveyor are seen in Stram et al Pat. No. 4009836 of Mar. 1, 1977 and Williams Pat. No. 4,830,291 of May 16, 1989. The Williams mill provides special features of construction to avoid the effect of blowback into the feed opening but does not prevent the impingement of uncrushables on the head shaft of the conveyor.